Vehicle seat tubing having variable wall thickness

ABSTRACT

Tubular bodies for use in frames for seats of vehicles such as aircraft are described. A tube can include a sidewall that has a variable thickness along the length of the tube. The variable thickness of the sidewalls can result in the tube having a variable inner diameter along the length of the tube. The tube may also include a variable outer diameter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 61/167,563, filed Apr. 8, 2009, and entitled “Variable WallThickness Tubing Principally for Aircraft Seats,” the entire contents ofwhich is incorporated herein by this reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to tubing for seats of a vehiclesuch as an aircraft and, more particularly to seat tubing having avariable wall thickness.

BACKGROUND

Seats in vehicles such as aircraft include frames for supportingcushions, pads, and other seating components. A frame can include one ormore base-frame tubes capable of providing support when the seatexperiences stresses caused by an individual in the seat during a crashlanding condition or caused by other activities. A base-frame tubeincludes a main tube and a second tube located in the inner diameter ofthe main tube. The second tube can provide local reinforcement to themain tube. The main tube and the second tube are fastened together usingrivets. The base-frame tube has a constant outer diameter.

Each of the main tube and the second tube has sidewalls of consistentthickness. The tubes are often made from extruded or drawn metal, suchas aluminum or steel. When loads are placed on the tubes, the secondtube can change position in the inner diameter of the main tube andcause uneven distribution of forces from stress at the abrupttransitions in overall tube sidewall thickness. Furthermore, such tubeconfigurations can be relatively heavy.

Accordingly, tubes are desirable that can distribute loads more evenly.Tubes are also desirable that weigh less and that can require lessassembly time. Tubes are also desirable that are configured to preventthe tubes from decoupling from additional components of frames.

SUMMARY

In one aspect, a frame for an aircraft seat is described. The frameincludes a wall of a tubular body. The wall includes a first portionthat has a first wall thickness and a second portion that has a secondwall thickness that is greater than the first wall thickness. The firstportion defines an inner diameter that is greater than an inner diameterdefined by the second portion.

In at least one embodiment, the wall of the tubular body includes athird portion that has an outer diameter that is greater than an outerdiameter of at least one of the first portion or the second portion.

In at least one embodiment, the third portion is the same thickness asthe second wall thickness.

In at least one embodiment, the third portion defines an inner diameterthat is smaller than the inner diameter of the second portion.

In at least one embodiment, the tubular body is made from at least oneof aluminum or steel.

In at least one embodiment, the tubular body is made from a cold formdrawing process.

In another aspect, a tubular body is described. The tubular bodyincludes a first portion and a second portion. The first portion has afirst wall thickness. The second portion has a second wall thicknessthat is greater than the first wall thickness. The first portion definesan inner diameter that is greater than an inner diameter defined by thesecond portion. The tubular body is a component of a frame for a seatcapable of being disposed in a vehicle.

In at least one embodiment, the tubular body also includes a thirdportion that has an outer diameter that is greater than an outerdiameter of at least one of the first portion or the second portion.

In at least one embodiment, the third portion is capable of preventingthe tubular body from decoupling from another component of the frame.

In at least one embodiment, the vehicle is an aircraft.

In another aspect, a seat for an aircraft includes a frame that has atubular body. The tubular body includes three portions. The firstportion has a first wall thickness. The second portion has a second wallthickness that is greater than the first wall thickness. The firstportion defines an inner diameter that is greater than an inner diameterdefined by the second portion. The third portion has an outer diameterthat is greater than an outer diameter of at least one of the firstportion or the second portion.

These illustrative aspects and embodiments are mentioned not to limit ordefine the invention, but to provide examples to aid understanding ofthe inventive concepts disclosed in this application. Other aspects,advantages, and features of the present invention will become apparentafter review of the entire application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a frame of a seat for a vehicle that,such as an aircraft, that includes a tubular body according to oneembodiment of the present invention.

FIG. 2 is a perspective view of a tubular body according to oneembodiment of the present invention.

FIG. 3 is a cross-sectional view of a tubular body according to oneembodiment of the present invention.

FIG. 4A depicts a load distribution of a prior art tube.

FIG. 4B depicts a load distribution of a tubular body according to oneembodiment of the present invention.

DETAILED DESCRIPTION

Certain aspects and embodiments of the present invention are directed totubular bodies for use in frames for seats of vehicles such as aircraft.A tube according to some embodiments includes a sidewall that has avariable thickness along the length of the tube. The variable thicknessof the sidewalls can result in the tube having a variable inner diameteralong the length of the tube. The variable thickness can distributeloads from stress more evenly than traditional tubes. Furthermore, atube may not require that a second tube be inserted in an inner diameterand coupled, reducing assembly time and decreasing the weight of thetube. A tube according to various embodiments of the present inventioncan be made from any suitable material. Examples of suitable materialinclude metal and composite material.

In some embodiments, a tube has a variable outer diameter along thelength of the tube. The variable outer diameter can prevent the tubularbody from decoupling from another component of the frame. The frame canprovide support for a seat of a vehicle such as an aircraft.

FIG. 1 depicts a frame 102 of an aircraft seat 104 according to oneembodiment. The frame 102 includes various coupled components thatprovide support for the seat 104. The components of the frame 102 inFIG. 1 include two tubular bodies 106, 108. Frames according toembodiments of the invention can include any number of tubular bodies.The seat 104 in FIG. 1 can be completed by attaching cushions (notshown) to the tubular bodies 106, 108 and positioned a bottom pan (notshown) between the tubular bodies 106, 108 and a bottom frame component110, which may also be a tubular body. In some embodiments, the bottomframe component 110 is a baggage bar. Any of tubular bodies 106, 108 orbottom frame component 110 may be a tube according to certainembodiments of the present invention. For example, tubular body 106 caninclude a variable wall thickness and can include a variable outerdiameter. The tubular body 106 can be made from any suitable material.Examples of suitable materials include aluminum and steel.

FIG. 2 depicts a perspective view of a tubular body 202 that includes avariable outer diameter. The tubular body 202 has one portion 204 withan outer diameter that is larger than the outer diameter of a secondportion 206. The tubular body 202 also includes a third portion 208 withan outer diameter that is larger than the outer diameter of the secondportion 206. In some embodiments, the outer diameter of the thirdportion 208 is the same as the outer diameter of the portion 204. Thelarge outer diameter portions can increase the strength of the tube,increase the weight of the tube, make the frame stiffer, and transferloads directly to the frame. The variable wall thickness of the tubularbody 202 can reinforce portions of the tubular body 202 that experienceshigher stress, such as by distributing the load and absorb and dissipateenergy. In some embodiments, the large outer diameter portions canprevent seat structures, such as legs or spreaders, from slipping out ofthe tubular body 202 during dynamic crash loading, or otherwise.

In other embodiments, a tubular body has a constant outer diameter sothat is and/or a leg or other frame component can be installed at anylocation.

Tubular bodies according to some embodiments of the present inventioncan also include a variable inner diameter and/or a variable sidewallthickness. FIG. 3 depicts a cross-section of a tubular body 302according to one embodiment. The tubular body 302 may be a single pieceof tubing that has a first portion 304 with an inner diameter that isgreater than an inner diameter of a second portion 306. The firstportion 304 may also include a sidewall that has a thickness that isless than the thickness of the sidewall at the second portion 306.Variable sidewall thickness can be created using any suitable process,such as a cold form drawing technique. U.S. Pat. No. 4,615,500 toAlexoff and U.S. Patent Pub. No. 2006/0112558 to Lorenz, et al. describeexamples of suitable processes of making variable wall thickness tubing.

The tubular body 302 can include any number of varied outer diameters,wall thicknesses (including constant thickness lengths and taperingthickness lengths). FIG. 3 depicts tubular body 302 as also including aportion 308 having a greater outer diameter than other portions of thetubular body 302. Tubular bodies according to other embodiments,however, include a variable sidewall thickness and/or varying innerdiameters, but do not include a varying outer diameter.

The tubular body 302 can be constructed to avoid abrupt transitions ininner diameter variation. For example, the tubular body 302 cantransition from the inner diameter of the first portion 304 to thelesser inner diameter of the second portion 306 via transition portion310 that has an inner diameter that decreases from the first portion 304to the second portion 306.

A tubular body according to some embodiments of the present inventioncan alleviate tube stress more evenly as compared to traditional tubes.FIGS. 4A and 4B include graphs that depict stress along portions of atraditional tube 402 in FIG. 4A and a tubular body 452 according to oneembodiment of the present invention. The traditional tube 402 introducesabrupt transitions 404, 406 in tube thickness resulting in unevenstresses 408, 410 along the tube length. The tubular body 452 can yielda constant stress 454 along the tube length. Furthermore, the tubularbody 452 can be easier to assemble and can provide lighter weightconstruction as compared to traditional tube 402.

The foregoing description of the embodiments, including illustratedembodiments, of the invention has been presented only for the purpose ofillustration and description and is not intended to be exhaustive or tolimit the invention to the precise forms disclosed. Numerousmodifications, adaptations, and uses thereof will be apparent to thoseskilled in the art without departing from the scope of this invention.

1. A frame for an aircraft seat, the frame comprising: a wall of atubular body, the wall comprising a first portion having a first wallthickness and a second portion having a second wall thickness that isgreater than the first wall thickness, wherein the first portion definesan inner diameter that is greater than an inner diameter defined by thesecond portion.
 2. The frame of claim 1, wherein the wall of the tubularbody further comprises a third portion having an outer diameter that isgreater than an outer diameter of at least one of the first portion orthe second portion.
 3. The frame of claim 2, wherein the third portionis the same thickness as the second wall thickness.
 4. The frame ofclaim 2, wherein the third portion defines an inner diameter that issmaller than the inner diameter of the second portion.
 5. The frame ofclaim 1, wherein the tubular body is made from at least one of aluminumor steel.
 6. The frame of claim 1, wherein the tubular body is made froma cold form drawing process.
 7. An tubular body comprising: a firstportion having a first wall thickness; and a second portion having asecond wall thickness that is greater than the first wall thickness,wherein the first portion defines an inner diameter that is greater thanan inner diameter defined by the second portion, and wherein the tubularbody is a component of a frame for a seat capable of being disposed in avehicle.
 8. The tubular body of claim 7, further comprising a thirdportion having an outer diameter that is greater than an outer diameterof at least one of the first portion or the second portion.
 9. Thetubular body of claim 8, wherein the third portion is the same thicknessas the second wall thickness.
 10. The tubular body of claim 8, whereinthe third portion is capable of preventing the tubular body fromdecoupling from another component of the frame.
 11. The tubular body ofclaim 7, wherein the tubular body is made from at least one of aluminumor steel.
 12. The tubular body of claim 7, wherein the tubular body ismade from a cold form drawing process.
 13. The tubular body of claim 7,wherein the vehicle is an aircraft.
 14. An seat comprising a frame, theseat being for an aircraft, the frame comprising a tubular body, thetubular body comprising: a first portion having a first wall thickness;a second portion having a second wall thickness that is greater than thefirst wall thickness, wherein the first portion defines an innerdiameter that is greater than an inner diameter defined by the secondportion; and a third portion having an outer diameter that is greaterthan an outer diameter of at least one of the first portion or thesecond portion.
 15. The seat of claim 14, wherein the third portion isthe same thickness as the second wall thickness.
 16. The seat of claim14, wherein the tubular body is made from at least one of aluminum orsteel.
 17. The seat of claim 14, wherein the tubular body is made from acold form drawing process.
 18. The seat of claim 14, wherein the thirdportion is capable of preventing the tubular body from decoupling fromanother component of the frame.